Refractory article and method of manufacturing the same.



NITED sTATEs PATENT ornea:

THOMAS B. ALLEN, or NfAGAn-A FALLS, NEW YORK, ASSIGNOR TO THE cAanoR uN- DUM COMPANY, or NIAGARA FALLS, NEW YORK, A CORPORATION or PENNSYL- VANIA.

No Drawing.

subject of the King of 'Great Britain,

siding at Nia ara Falls, in the countypf Niagara and tate of New York, have invented a new and useful Improvement in Refractory Articles and Methods of Manufacturing the Same, of which the following is a full, clear, and exact description.

This invention has relation to a new and useful refractory article and also to a new and useful method of manufacturing the same. A

Artificial crystalline alumina has many physical and chemical properties which render it valuable in the manufacture of re,- fractory articles. Heretofore, the manufacture of such articles has been accomplished by bonding the crystalline alumina yvith clay orother suitable material and vitrifying the mixture in a ceramic kiln. This method of manufacture, however, obviously reduces the refractoriness of the finished articles, due to the fluxing action of the bond on the crystalline alumina and the lowered vitrifying temperature of the mess.

I have discovered that a very superior article can be produced by bonding crystalline alumina with a material which is identical in chemical composition therewith; I there by obtain articles of very great refractoriness, which have, in fact, substantially the same melting point as pure alumina, I accomplish this result by bonding the crystalline -alumina with anamorphous alumina of a more or less colloidal nature,

then shaping the articles from the plastlc mass, and finally heating to a temperature sufficient to set the amorphous alumina.

A preferred method of carrying out my invention is asfollows. I take a warm saturated solution of ammonium aluminum sulmonium .hydroxid.

fate and precipitate the alumina with amwashed with hot water andfilter A sufficient quantity of this material is taken to give, preferably,

mixedwith crstalline alumina; of a suite-f ble degree of neness. The wet mass is al lowed to dry'giowly in order toincrease the plasticity, and-Twhen in a suitable state is pressed or otherwise Specification of Letters Patent. Application filed November 18, 1913 I Serial No. 800,769.

slowly and when The precipitate is pressed.

from five to ,ten percent." lay-weight of the finished article, and thisjis alumina with aluminum hydroxid,

fashioned into shape.

REFRACTORY ARTICLE A D METHOD or MANUFACTURING TnEsAivin Patented Aug.

then allowed to dry v dry has suificient mechanical strengthto be handled. It is then placed in a pottery kiln andheated to a temperature suflicient to set the amorphous alumina, a temperature of from l300 to 1400 C. being preferably employed, although the articles will have lcal strength if a lower temperature is used. Articles'formed in this manner have very superior refractory properties, since they consist essentially of pure alumina. They also have a fairly high mechanical strength.

The shaped article is a fair mechan- This quality can be improved by the addition of; glyceroboric' acid to the mixture. This may be done by mixing with the mass a solution of boric acid and glycerin. The

quantity of this solution need not exceed five per cent. of the total mixture. This particular feature of the process is not, however, claimed broadly in the present application, as it forms the subject matter of my copending application Serial N 0. 753,468. The addition of this substance gives a higher mechanical crystalline alumina, and when used in conjunction with the present process, yields a product of a very highly refractory nature.

I do not desire to limit myself to the exact details of the process herein described, as they may be departed from in various ways Within the scope ofthe appended claims without affecting my invention.

I claim:

1. The method of making refractory articles, which consists in bonding crystallinealumina with amorphousv alumina.

I 2. The method of making refractory arstrength to articles ofmoles, which consists in/mixing crystalline alumina with aluminum hydroxid, shaping the mixture, and then heating to a temperature sufiicient to set the amorphous alumina.

p 3. Themethod of making refractory articles, which consists in mixing crystalline alumina with aluminum hydroxid, shaping the mixture, and then heating to a relatively high temperature.

'4. The method of. making refractory articles, which consists in mixing crystalline shaping the mixture, and then heating to a tempera- I ture of at least 1200 C.

5. The method of making refractory articles, which consists in bonding crystalline alumina with amorphous alumina and glyceroboric acid.

6. The process of making refractory articles, which consists in mixing crystalline alumina with aluminum hydroxid and glyceroboric acid, and then shaping the mixture and heating to a relatively high temperature.

7. The process of making refractory articles which consists in mixing crystalline alumina with aluminum hydroxld and glyceroboric acid, and then shaping the mixture and heating to a temperature of at least 1200 C.

8. In the manufacture of refractory articles, the method of binding a crystalline refractory compound with a collodial form of the same compound.

In testimony whereof, I have hereunto set my hand.

THO S. B. ALLEN.

Witnesses ,C, J. BROCKBANK, CHARLES N. SCOTT. 

